Israeli troops began moving into the heart of the southern Gaza town of Rafah, one day after fighting in the adjacent refugee camp left at least 20 Palestinians dead. The Israeli Army says it shot and killed two more Palestinian gunmen. The military says it expects to meet intense resistance as it continues a major operation to destroy weapons smuggling tunnels and arrest or kill Palestinian militants.

Israeli troops destroyed the Rafah home of a Palestinian gunman who had shot and killed a Jewish woman and her four daughters earlier this month in southern Gaza.

Israel says it carried out the demolition to discourage other Palestinians from attempting to carry out terror attacks.

The demolition marked the start of an effort by Israeli troops to widen the scope of the operation from the Rafah Palestinian refugee camp to the center of the town.

In one neighborhood, Israeli forces demanded that all males aged 16 and over gather at the local school for interrogation by the soldiers.

Palestinian Cabinet Minister, Ghassan Khatib, says world opinion is against Israel, and the international community must now take measures to stop the military operation in Gaza.

"The American Government has criticized this demolition of houses. The United Nations Secretary-General [(Kofi Annan] has also criticized this policy, but we now require the international community and the United Nations in particular to take the necessary practical steps to stop the Israelis from killing Palestinians and demolishing their houses," he said.

Despite such criticism, the Israeli Army says the operation will continue until it destroys all tunnels used to smuggle weapons and explosives across the border into Gaza from neighboring Egypt.

Israel says many of those killed in the operation were Palestinian gunmen. Palestinians say civilians were also killed, including children.

Israeli Army spokeswoman Major Sharon Feingold says the raid only aims to target Palestinian militants, who she says are putting the lives of civilians at risk by operating inside Rafah.

"The purpose of the operation is not to demolish houses, I repeat we do not systematically demolish houses," he said. "We are operating against these tunnels, unfortunately the terrorist cells which operate in Rafah make use of the civilian population, of the civilian infrastructure to dig these tunnels and to operate this conglomerate of terror."

Meanwhile, Israeli forces launched separate raids into two West Bank towns, killing two members of the Al-Aqsa Martyrs' Brigades, an armed wing of Palestinian President Yasser Arafat's Fatah faction.